Adjustable geneva intermittent



May 5, 1931.-- DINA 1,803,465

ADJUSTABLE GENEVA INTERMITTENT Filed Nov. 30, 1928 3 Sheets-Sheet 1zip/.-

INVENTOR.

4,; ATTORNEY May 5, 1931. A. DINA 1,803,465

ADJUS TABLZE GENEVA INTERMITTENT Filed Nov. 30, 1928 3 Sheets-Sheet 2INVENTQR; PwgusYoDuqo. BY W Q A TTORNEY May 5, 1931. A 1,803,465

ADJUSTABLE GENEVA INTERMITTENT Filed Nov. 30, 1928 5 Sheets-Sheet 3 vINVENTOR.

BUQUST Divqo v A, ATTORNEY Patented May 5, 1931 UN TED STATES AUGUSTODINA, oFJnnsa-Y oIrY, iv rwannsnm ASSIGNQR/TO" mTERN rIoNALrRm JEGTORCORPORATION, oFnEw YonK, N. Y A CORPORATION OF DELAWARE.

ADJUSTABLE GENEVA INTERM ITTET N T :Application filed November 30,1928.Serial No. 322,696.

This invention relates to intermittent mechanical movements, and moreparticularly to mechanism for driving the intermittent sprocket of amotion picture projecting apparatus. The invention is appliedspecifically to the well known Geneva movement wherein one elementisintermittently rotated by means of a continuously rotated drivingelement and provides means for ad justing the same to compensate forwear or inaccurate workmanship.- 3

The Geneva movement, vasemployed in motion picture projecting apparatusfor.

causing intermittent 1 rotation of the film sprocket, I comprisesastarwheel having radially extending slots and a continuously rotating memberhaving a pin for engaging saidslots, and acam for cooperating withasurfajce of said star wheel when the pin is disengaged. Upon eachrevolution ,of the continuously rotating member, the pin: enters aslotin-the star wheel and rotates the wheel through an angle of 90:degrees,there-.

by bringing the next slot into pin-receiving position. The cam surface.holds the star wheel stationary while the pin is disengaged, andmaintains the slot in proper position with respect to the line of travelof the pin. hen the surfaces of the star wheel and ofthe cam have becomeworn, the starwheel will no longer be rigidly securedagainst movement,but will be f-ree'to rotate through a certain limited angle. Thisangularmovement may be suflioiently great tohthrow the slot in the star wheelout of alignment with the pin on the rotating. member and, cause thepin, instead of entering the slot, to strike against the sides; thereon.Thismay result inbending or-breaking the points of the star wheel orinjury to the pin itself.

The present invention providesmeans for accurately adjusting therotating member and. "the star ,wheel to compensate for: wear and-forvaiviations in the manufacture thereof; while accurately mamta nlng thealignment of the various parts, whereby the pin is at all timesprevented from contacting with the sides of the slots. i

This is accomplished by formin the cam,

and the cooperating portions of the star respective centerson throwingthe pins and slots out of alignment. r e

The invention also consists in certain new and original features ofconstruction and combinations of parts hereinafter setforth and claimed.f v 1 1 Although the novel features which are be lieved to becharacteristic of this invention will be particularly pointedout in theclaims appended hereto, the invention itself, asto its objects andadvantages, the mode of its operation and the manner of itsorganizationmaybe better understood by referringto the following description taken-.in"connec tion with the accompanying drawings forming a part thereof,in which Fig. 1 is a longitudinal sectional view of the intermittentsprocket and driving means therefor; v V V Fig. 2is a section taken onthe line 2-2 of Fig. .1; i i

Fig. 3 is an enlarged and driving member; I

Fig. 1 is an enlarged sectional view showin g the star wheel anddrivin'g member as initiallyassembled; Fig. 5 is a sectional viewsimilar to Fig. 4

View of the star wheel showing the parts after adjustment for wear hasbeen made; I p i i v s Fig. 6 is a diagrammatic illustration of themovement of the inclined surfaces for ad-.

rious relative positions of the two elements; and

Figs. 11 and 12 are elevations of star wheels which have been damageddue to improper alignment.

Like reference characters denote like parts in the several figures ofthe drawings.

In the following description and in the claims parts will be identifiedby specific names for convenience, but they are intended to be asgeneric in their application to similar parts as the art will permit.

Referring to the drawings more in detail, the invention is shown asapplied to a Geneva movement comprising a base member or housing inwhich shafts 11 and 12 are journalled.

Shaft 11 is rot-atively held in bearings 13, secured in said housing 10and shaft 12 is journalled in sleeve 14, which may be rigidly secured tohousing 10,- as by means of screw 15 passing through an extension insaid sleeve and into an aligned opening in said housing.

Sprocket wheel 16 is rigidly secured to rotating shaft 11 and rotates inconjunction therewith, said sprocket being adapted to en gage motionpicture film and direct the same past the aperture plate of a projectingapparatus (not shown). Star wheel 17 is secured to the end of shaft 11for driving the same in the manner to be hereinafter set forth. Saidstar wheel comprises a plurality of tapered or frustro-conical surfaces18 and a plurality of radially extending slots 1.9,said slots beingspaced around the periphery of said wheel by angles of 90 degrees.

Driving gear 20 and flywheel 21-are rigidly secured to shaft 12, saiddriving gear being adapted to receive power from a cooperating gearwheel (not shown). Flywheel 21 is designed to have sufficient inertia toprevent undue vibrations of the apparatus due to the sudden starting andstopping of the intermittent sprocket 11. Idler shaft 22 is journalledin sleeve 23, said sleeve being adj ustably secured in housing 10, as byset'scr'ew 30. Gear wheel24is rigidlysecured to said shaft 22 and isadapted to mesh with gear wheel 25 carried on the end of shaft 12.Member 26, having a frustro-conical cam surface 27 and a pin 28, issecured to shaft 22 adjacent gear wheel 24 and rotates in conjunctiontherewith.

Pin 28 is adapted to enter slot 19 in star wheel 17 and to rotate saidstar wheel through 90 degrees with each revolution of shaft 22. Cam 27on member 26 cooperates with curved surface 18 on star wheel ,17 forpreventing movement of the star wheel while pin 28 is disengaged fromslot 19. Shaft 22 may be longitudinally adjusted for bringing cam 27 andsurface 18 into intimate contact by moving sleeve 23 in housing 10 andfirmly securing the same as by means of set screw 30. The teeth of gearwheel 24 should preferably be sufficiently long to allow the desiredlongitudinal movement of shaft 22 without becoming disengaged from thecooperating teeth on gear wheel 25.

Referring to Fig. 4, the relative position between cam member 26 andstar wheel 17 shown before wear of the cooperating surfaces has takenplace. Fig. 5 shows the relationship subsequent to such wear and aftercam member 26 has been moved longitudinally by a sufficient distance tocompensate therefor, said movement again bringing surfaces 27 and 18into engagement.

In the operation of the above described apparatus, shaft 22 and cammember 26 are continuously rotated in response to rotation of shaft 12which is driven by any suitable source of power. Member 26, in rotating,causes pin 28 to enter a slot 19 in star wheel 17 and to turn said wheel17 through 90 degrees. Cam 27 then cooperates with curved surface 18 andrigidly secures star wheel 17 against further movement after said pin 28has become disengaged from said slot. The relative position of theparts, while surfaces 27 and 18 arein'engagemenais more clearly shown inFig. 3. Cam surface 27 is designed to securely hold star wheel 17 untilpin 28 is again in position to enter a slot 19. Surface 18 is thenreleased and a further 90 degree rotation of the star wheel permitted.

In the operation thus far described, it has been assumed that the partsare maintained in accurate alignment and that no wear has taken place.This condition is indicated in Fig. 7 wherein pin 28 is about to enterslot 19 in star wheel 17, the star wheel, however, being still engagedby surface 27, whereby the axis of slot'19'is caused to'coincide withthe axis of pin 28. a

After wear has taken place, surfaces 27 and 18' may no longer 'be'inaccurate engagement and'may become spaced apart as shown in Fig. .8.This condition may, of course, be obtained due to the wear "of the partsor due to inaccurate workmanship or faulty assembly. As shown in Fig. 8,the axis of slot 1.) still coincides with the'axis of pin 28, wherebythe pin will freely enter the slot and cause the desired rotation ofstar wheel 17. There is, however, no means for positively holding starwheel 17 in this position since surfaces 27 and 18 are now out ofengagement. In fact, it would be extremely unlikely that such positionwould be assumed unless some positive means is provided for insuring thesame.

Figs. 9 and 10 show the cam member 26 as slightly raised as in the oldform of construction of the Geneva movement in an effort to compensatefor the wear of the surfaces and to again bring the two parts in theirdesired relationship. In Fig. 9, although surfaces 18 and 28 are notbrought into exact contact, star wheel 17 is shown in its most favorableposition for receiving pin 28. It 'may be isms-5- I noted, however, thatthe axis of slot 19 no longer coincides with the axis of said pin andthat upon further rotation of the cam memher, the pin 28 will contactwith the side of slot 19. Fig. 10 shows the condition which would obtainif star wheel 17 were rotated slightly from its optimum position, suchrotation being allowed by the clearance between surfaces 27 and 18. Inthis position, pin 28 will positively bear against one of the sides ofslot 19 with consequent injury to the apparatus. The sides of the slotor points, would be broken as shown in Fig. 11 or bent as shown in Fig.12.

It is obvious therefore that a vertical a'dj ustment of shafts 11 and 22as shown in Figs. 9 and 10 cannot be employed for bringing surfaces 18and 27 into contact. In accordance with the present invention, however,these two surfaces are constructed of a conical form, and adjustment isobtained by a relat-ive longitudinal movement of shafts 11 and 22. Inthe specific embodiment disclosed, shaft 22 is adapted to be movedlongitudinally by means of sleeve 23 and to be securedin any desiredposition as by set screw 30, although any other means may be employed ifdesired for causing the necessary relative movement of the parts. a

The adjustment is more clearly indicate in Fig. 6 wherein AB representsa portion of cam surface 27 and CD represents a cooperating portion ofsurface 18. The surfaces are inclined to their axes by the angle BOF.When surfaces 18 and 27 are worn down to lines GH and IK respectivelythey may again be brought into contact by moving surface 26 to the left,parallel to the axis OF by the distance HK.

It is evident that the alignment of the pin and slot, in the rotatingmember and star wheel respectively, is not altered by the aboveadjustment since the position-of the axes of the two members is notchanged thereby and the distance between centers is not varied.Consequently the line of movement of the pin during the rotationthereof, and the axes of the slots in star wheel 17, will remain inpredetermined relationship. BOF is less than 90 degrees, a comparativelylarge movement is required along the axis OF, in order to compensate fora small variation in the cooperating surfaces. The accurate adjustmentof the two members is therefore facilitated.

In accordance with the present invention.

by means of which cam 27 and surface 18 of the star wheel, aremaintained in accurate adjustment, the slots in the star wheel arecontinually held in alignment with the line of travel of the pin. Thepin is therefore prevented from contacting with the sides of the slotsand from damagingthe points of the star wheel. In fact, it has beenfound, in an apparatus constructed as above described,

Since the angle that the life of the star wheel is materially increasedand "with'a resulting decrease in cost of maintenance. In the drawingsaccompanying and forming part of this specification, a practicalcommercial) embodiment of the invention is shown, but as suchillustration'is primarily for purposes ofdisclosure, it will beunderstood that the structure may be modified in various respectswithout departure from the broad spiritand scope-of the invention ashereinafter defined and claimed. Vfhat is claimed is: I

1. In a motion picture apparatus, a sprocket adapted to "beintermittently rotated through comparatively small angles, a shaftcarrying said sprocket and rigidly secured thereto, means for rotatablymounting said shaft, a star wheel secured to said shaft and having aplurality of radially extending slots and cam surfaces therebetween,meansfor said first mentioned cam surfaces, said cam surfaces beingtapered 1n the direction of their axes whereby relative longitudinaladjustment thereof serves to'maintain said surfaces in engagement, adriving shaft rigidly secured to said pin wheel and carrying a drivinggear, a bushing rotatably mounting said driving shaft and supporting thesame against longitudinal movement, a support for said bushing, meansfor adjusting said bushing longitudinally of said driving shaft andclamping said bushing in said support, a gear substantially coaxial withsaid star wheel and in driving engagement with said driving gear, ashaft supporting said last mentioned gear wheel and a fly wheel carriedby said shaft for maintaining substantially constant rotation thereofwhile said sprocket is being intermittently rotated.

star wheel comprising a pin wheel having a pin adapted to engage saidslots and a cam surface adapted to engage said first mentioned camsurfaces, said cam surfaces being tapered in the direction of their axeswhereby relative longitudinal adjustment thereof serves to maintain saidsurfaces in engagement, a driving shaft rigidly secured to said pinwheel and carrying a driving gear, a bushing rotatably mounting saiddriving shaft and supporting the same against longitudinal moveita iii)

ment, a support for said bushing, means for adjusting said bushinglongitudinally of said driving shaft and clampingsaid bushing in saidsupport, a gear substantially coaxial with said star Wheel andiii-driving engagementwith said driving gear, a shaft supporting saidlast mentioned gear Wheel and a fly Wheel carried bysaid shaft ,f'orrnaintaining substantially constant rotation thereof While said sprocketis being intermittently rotated, the arrangement permitting longitudinaladjustment of the pin Wheel .to compensatefor wear While maintainingsaid sprocket in its original optical position.

AUGUSTO DINA.

